Design of a grating by a joint optimization method for a phase-shifting point diffraction interferometer

• DOI: 10.3788/col201715.101203
• Publication Date: 2017-08-31T08:12:28Z
• Authors: Meng Zheng Meng Z...; Ke Liu Ke Liu; Lihui Liu Lihui Liu; Yanqiu Li Yanqiu Li
• Keywords: 0103 physical sciences; 01 natural sciences

A grating is an important element of a phase-shifting point diffraction interferometer, and the constant duty cycle have great impact on so design becomes significant. In order to measure projection objective with numerical aperture 0.2, we present joint optimization method pinhole based scalar finite difference time domain method. The film thickness are selected, optimized. results show that in processing material chromium adopted, 200 nm, 15 μm. When 55%, interference fringe contrast greatest. feasibility result further verified by experiment.